CRITICAL-EVALUATION AND OPTIMIZATION OF THE THERMODYNAMIC PROPERTIES AND PHASE-DIAGRAMS OF THE CAO-AL2O3, AL2O3-SIO2, AND CAO-AL2O3-SIO2 SYSTEMS

All available thermodynamic and phase diagram data have been critically assessed for all phases in the CaO-Al2O3, A12O3-SiO2, and CaO-Al2O3-SiO2 systems at 1 bar pressure from 298 K to above the liquidus temperatures. All reliable data for the binary systems- have been simultaneously optimized to obtain, for each system, one set of model equations for the Gibbs energy of the liquid slag and all solid phases as functions of composition and temperature. The modified quasichemical model was used for the slag. With these binary parameters and those from the optimization of the CaO-SiO2 system reported previously, the quasichemical model was used to predict the thermodynamic properties of the ternary slag. Two additional small ternary parameters were required to reproduce the ternary phase diagram and ternary activity data to within experimental error limits. The calculated optimized phase diagram and thermodynamic properties are self-consistent and are the most reliable currently available estimates of the true values.